(1) Field of the Invention
This invention pertains to a system to remove frac plugs in a well.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Oil or gas wells often have in the ground multiple formations. When there is a need to fracture individually these formations to stimulate them to better produce oil, temporary plugging agents or “frac plugs” are set at desired elevations in the well casing or bore to facilitate fracturing the formations in stages. After each desired formation has been fractured, the frac plugs are removed to enable operation of the well to produce oil or gas. Frac is a shorthand term for fracturing in connection with oil and gas wells.
Composite frac plugs are often utilized. These frac plugs include or incorporate a resin in combination with a ceramic, cloth, aluminum, cast iron and/or some other material. For example, one frac plug includes a resin body in combination with an aluminum mandrel and cast iron slips. Still another frac plug includes a resin body in combination with ceramic inserts. Some examples of commonly used composite frac plugs include the MILL EZ™ by Magnum Oil Tools, the SPEEDY LINE II™ by Halliburton, the QUICK DRILL 2™ by Baker Oil Tools, the PYTHON MT™ by BJ Services, the D2™ by Smith Services, and the FRACGUARD™ by Weatherford Completion Systems.
Conventional mills have long been utilized to remove frac plugs, as well as other materials including steel, cast iron, cement, dehydrated drilling mud, and dehydrated sand slurries.